1) Technical Field
The invention relates to a method for manufacturing a breast prosthesis which substantially consists of bodies modeling the shape of the breast, which are shrink-wrapped in plastic films.
2) Description of Related Art
Breast prostheses are known already, in which these bodies modeling the breast shape consist of a transparent addition crosslinking two-component silicone-rubber compound. Since the silicone material is transparent by nature, the desired skin color is achieved by addition of small amounts of color pigments—for example by admixture of 0.2 wt-% of color pigment. Typically, polyurethane films are used as films enclosing the silicone. The same have a high elasticity and softness. Nevertheless, they are rather stiff as compared to the silicone used, so that the film tends to form wrinkles. Due to the transparency of the polyurethane film and the silicone, these wrinkles however are not clearly visible and therefore do not disturb.
By adding hollow spherical fillers which are used for weight reduction of the breast prostheses, a strongly covering white color is obtained in the lightweight silicone. This results from the fact that the hollow spherical fillers consist of a multitude of spheres which individually act as color prism. This phenomenon for example is comparable with transparent snow crystals which due to the refraction of light in sum likewise appear white. By addition of color pigments, the white color of the lightweight silicone can be changed in direction of an adaptation to the skin color. However, this is not reproduced as natural as it is possible with standard silicone. Due to these differences in color, the aforementioned wrinkles of the polyurethane film become much more visible due to the opaque color of the lightweight silicone and optically are perceived as disturbing.
To avoid the aforementioned problem, it has become known already to create a multilayer breast prosthesis, wherein on the outside a thin covering layer of standard silicone is formed on the front side, which is transparent and with the coloring adapted to the skin color provides an attractive appearance. From EP 0 880 951 B1 there is known a method for manufacturing a multi-chamber breast prosthesis, in which the manufacture of this so-called cosmetic layer is effected outside the prosthesis mold. In this known method it is disadvantageous that the cosmetic layer produced outside the prosthesis mold exhibits differences in thickness, i.e. does not have a uniformly thin outer layer. As a result, the attractive appearance which should be achieved by the comparatively thin covering layer frequently is achieved only insufficiently.
It now is the object of the present invention to develop a method which creates such prosthesis with a so-called cosmetic covering layer with constant thickness.